pilot study of high-concentration capsaicin patches in the treatment of painful hiv-associated neuropathy

Conditions: HIV Infections

Summary: the purpose of the study is to gain initial information on the tolerability and feasibility of high-concentration capsaicin patches for the treatment of painful hiv-associated neuropathy, whether resulting from hiv disease and/or antiretroviral drug exposure. the study will also provide preliminary safety and efficacy information.


Eligibility criteria:
inclusion criteria: * between 18 and 75 years of age. * documented evidence of hiv-1 infection. * painful hiv-associated neuropathy, whether resulting from hiv disease and/or antiretroviral drug exposure, with primary symptoms of pain, burning or dysesthetic discomfort in both feet for at least 2 months prior to screening visit. and: * diminished ankle reflexes (compared to the knee) or absent ankle reflexes, and/or * distal diminution of either vibration sensation or pain or temperature sensation in the legs. * either no neurotoxic antiretroviral (i.e., didanosine \[ddi\], zalcitabine \[ddc\], or stavudine \[d4t\]) exposure for at least 8 weeks prior to screening visit, or * currently on stable dose(s) of any of the neurotoxic antiretrovirals listed above for at least 8 weeks prior to screening visit, without a foreseeable need to change doses or medications for duration of study. * screening pain sum score of 12 to 36. * intact, unbroken skin over the painful area(s) to be treated. * if taking chronic pain medications, be on a stable (not prn) regimen for at least 7 days prior to treatment visit (day 0) and willing to maintain medications at same stable dose(s) and schedule throughout the study. * be willing and able to use roxicodone® (oxycodone) oral solution, if needed, to relieve treatment-associated discomfort. * female subjects with child-bearing potential must have a negative urine or serum pregnancy test, to be performed at the screening visit. * all subjects must be willing to use effective methods of birth control and/or refrain from participating in a conception process during the study and for 30 days following experimental drug exposure. * be willing and able to comply with protocol requirements for the duration of study participation. (such requirements include, but are not limited to: completing a daily pain diary, attending all study visits, and refraining from extensive travel during study participation.) exclusion criteria: * presence of acute, active opportunistic infection, except oral thrush; oral, genital, or rectal herpes; and mycobacterium avium bacteremia within 2 weeks prior to screening visit. * significant pain of an etiology other than painful hiv-associated neuropathy, for example, compression-related neuropathies, e.g., spinal stenosis, or fibromyalgia or arthritis. subjects must not have significant ongoing pain from other cause(s) that may interfere with judging hiv-associated neuropathy pain. * evidence of another contributing cause for peripheral neuropathy, e.g., diabetes mellitus, hereditary neuropathy, vitamin b12 deficiency (b12 level less than or equal to 200 pg/ml) or less than 3 months of b12 supplementation prior to screening visit, or treatment within 90 days prior to screening visit with any drug that may have contributed to the sensory neuropathy. * any implanted medical device (spinal cord stimulator, intrathecal pump or peripheral nerve stimulator) for the treatment of neuropathic pain. * recent use (within 21 days preceding the treatment visit \[day 0\]) of any topically applied pain medication, such as non-steroidal anti-inflammatory drugs, menthol, methyl salicylate, local anesthetics (including lidoderm®), steroids or capsaicin products on the painful areas. * treatment for acute opportunistic infections within 14 days before treatment visit (day 0). maintenance treatment of cytomegalovirus (cmv) retinitis, mycobacterium avium bacteremia, or cryptococcal meningitis is permitted. * current use of any investigational drug, or class 1 anti-arrhythmic drugs (such as tocainide and mexiletine). * hypersensitivity to capsaicin (i.e., chili peppers or otc capsaicin products), local anesthetics, roxicodone or adhesives. * significant ongoing or untreated abnormalities in cardiac, renal, hepatic, or pulmonary function that may interfere either with the ability to complete the study or the evaluation of adverse events. * currently have active malignant disease. malignancies in remission that do not require further treatment or kaposi's sarcoma requiring local treatment only are allowed. * high tolerance to opioids that precludes the ability to relieve treatment-associated discomfort with roxicodone® if needed, as judged by investigator. * history or current problem with prescription drug, illicit substance, or alcohol abuse from self report or as judged by investigator.

Keywords: pain measurement diary painful hiv neuropathy hiv neuropathy capsaicin analgesics/*therapeutic use capsaicin/*administration & dosage/adverse effects peripheral nervous system diseases/*complications/diagnosis/*therapy peripheral nervous system diseases/drug therapy/*etiology/physiopathology pain